Effect of the hysteretic response of elastomers on thefatigue life

Elastomers are widely used in automotive Anti-Vibration Systems (AVS). In this application, elastomeric parts are subjected to cyclic loading condition which lead to fatigue failure. Number of experimental investigations show that elastomeric materials exhibit stress-softening and hysteresis in these conditions. Numerous models have been proposed to capture the corresponding mechanical response but few attempts focus on the relationship between cyclic behavior and fatigue life prediction maybe due to the complex nature of phenomena. In this study, the qualitative relationship between hysteretic response and fatigue life prediction of elastomers is considered. A simple non-linear phenomenological three-parameter model is adopted to simulate the long-term (stabilized) hysteretic response of the material under uniaxial cyclic loading. In order to estimate fatigue life, only crack initiation is considered and the concept of configurational stress is adopted to define the end of life. Different stretch-controlled loading conditions are considered, i.e. the influence of both mean stretch and stretch amplitude is investigated in order to build the Haigh diagram. Thus, the effect of hysteretic response of elastomers on the fatigue life is discussed. The emphasis is laid on the prediction of the well-known reinforcement phenomenon classically observed for tension-tension loading conditions.